Quakers (or Friends) are members of a group of religious Christian movements which is known as the Religious Society of Friends in Europe, Australia, New Zealand and parts of North America; and known as the Friends Church in Africa, Asia, South America and parts of the US. The movements were originally, and are still predominantly based on Christianity. Members of the movements profess the priesthood of all believers, a doctrine derived from the First Epistle of Peter. They include those with evangelical, holiness, liberal, and traditional Quaker understandings of Christianity. To differing extents, the different movements that make up the Religious Society of Friends/Friends Church avoid creeds and hierarchical structures. In 2007, there were approximately 359,000 adult Quakers.